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[Bug middle-end/19988] [4.0 Regression] pessimizes fp multiply-add/subtract combo
- From: "pinskia at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 15 Feb 2005 23:42:26 -0000
- Subject: [Bug middle-end/19988] [4.0 Regression] pessimizes fp multiply-add/subtract combo
- References: <20050215225352.19988.stevenj@fftw.org>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From pinskia at gcc dot gnu dot org 2005-02-15 23:42 -------
Almost want to say this is caused by:
2004-07-11 Roger Sayle <roger@eyesopen.com>
* fold-const.c (fold) <PLUS_EXPR>: Canonicalize X + -C as X - C for
floating point additions, to keep real immediate constant positive.
<MINUS_EXPR>: For floating point subtractions, only transform X - -C
into X + C, and leave positive real constants as X - C.
http://gcc.gnu.org/ml/gcc-patches/2004-07/msg01155.html
Confirmed.
--
What |Removed |Added
----------------------------------------------------------------------------
CC| |roger at eyesopen dot com
Severity|normal |minor
Status|UNCONFIRMED |NEW
Ever Confirmed| |1
Last reconfirmed|0000-00-00 00:00:00 |2005-02-15 23:42:25
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19988